Nice theory.
CompilerResultsLog: Info Creating library C:\Users\\Documents\Unreal Projects\MM_04\Intermediate/Build/Win64\UE4Editor\DebugGame\UE4Editor-MM_04-3484-Win64-DebugGame.lib and object C:\Users\\Documents\Unreal Projects\MM_04\Intermediate/Build/Win64\UE4Editor\DebugGame\UE4Editor-MM_04-3484-Win64-DebugGame.exp
CompilerResultsLog:Error: Error Module.MM_04.cpp.obj : error LNK2019: unresolved external symbol "public: bool __cdecl ULevelStreaming::IsLevelVisible(void)const " (?IsLevelVisible@ULevelStreaming@@QEBA_NXZ) referenced in function "public: bool __cdecl FLevelLink::IsLoading(void)const " (?IsLoading@FLevelLink@@QEBA_NXZ)
CompilerResultsLog:Error: Error C:\Users\\Documents\Unreal Projects\MM_04\Binaries\Win64\UE4Editor-MM_04-3484-Win64-DebugGame.dll : fatal error LNK1120: 1 unresolved externals
CompilerResultsLog: Info -------- End Detailed Actions Stats -----------------------------------------------------------